Single Soul golems have the weakest bonuses, but are cheap to make. You start with 3 of these and it is recommended that your first few golems be these due to how the game works.


Beast:
1 Beast Soul
Effect:

• Beast Influence: Movement Speed +10%

Bird:
1 Bird Soul
Effect:

• Bird Influence: Build +10%; Repair +10%

Human:
1 Human Soul
Effect:

• Human Influence: Production +10%; Cooking +10%

Mecha:
1 Mecha Soul

• Mecha Influence: Mining +10%

Insect:
1 Insect Soul
Effect:

• Insect Influence: Farming +10%; Harvest +10%

Two Soul golems have potentially medium bonuses, aren't too expensive, and probably won't be used much. Pures have no penalties.

Beast:
2 Beast Soul
Effect:

• Beast Influence+: Movement Speed +25%

Bird:
2 Bird Soul
Effect:

• Bird Influence+: Build +25%; Repair +25%

Human:
2 Human Soul
Effect:

• Human Influence+: Production +25%; Cooking +25%

Mecha:
2 Mecha Soul

• Mecha Influence+: Mining +25%

Insect:
2 Insect Soul
Effect:

• Insect Influence+: Farming +25%; Harvest +25%

Triple Soul golems have high bonuses and are best for late game. Pures have no penalties.

Beast:
3 Beast Soul
Effect:

• Beast Influence++: Movement Speed +50%

Bird:
3 Bird Soul
Effect:

• Bird Influence++: Build +50%; Repair +50%

Human:
3 Human Soul
Effect:

• Human Influence++: Production +50%; Cooking +50%

Mecha:
3 Mecha Soul

• Mecha Influence++: Mining +50%

Insect:
3 Insect Soul
Effect:

• Insect Influence++: Farming +50%; Harvest +50%

Impurity gives penalties. The bonuses will still be based on the souls used. (So 2 mecha will give the 2 mecha bonuses).

Now, not every combination will result in a penalty. Penalties are applied at semi-random.
* All/Penta type penalty is always applied from my testing, so you should never make penta types.

Note that you can have penalties that overshadow the bonuses gained. (For example, you can have a mecha soul with +50% Mining and then have Refusal: Repair Mine Harvest where it can't mine.

The body penalty seems to be most common for each group.

Due to the random nature of penalties, this is not an exhaustive list:
Dual Type Penalties:

• Tired Body: +50% Food consumption
  
• Bad Arm: Repair -50%; Harvest -50%
  
• Bad Fingers: Production -50%; Farming -50%
  
• Bad Leg: -50% Movement Speed

Triple Type Penalties:

• Exhausted Body: +100% Food consumption
  
• Conflict: [Activity] : Cannot do [Activity]

Quad Type Penalties:

• Worn Out Body: +100% Food Consumption; HP Loss
  
• Refusal: [Activity] [Activity] [Activity]: Cannot do any [Activity] listed (Repair Mine Harvest seems to be the usual)

All Type Penalties:

• Perishing Body: HP Loss; HP Cannot be recovered